[C:1]([Si:5]([CH3:14])([CH3:13])[O:6][C@@H:7]1[CH2:11][CH2:10][C@H:9](O)[CH2:8]1)([CH3:4])([CH3:3])[CH3:2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O.C1(P([N:60]=[N+:61]=[N-:62])(C2C=CC=CC=2)=O)C=CC=CC=1>O1CCCC1>[N:60]([C@H:9]1[CH2:10][CH2:11][C@H:7]([O:6][Si:5]([C:1]([CH3:4])([CH3:3])[CH3:2])([CH3:14])[CH3:13])[CH2:8]1)=[N+:61]=[N-:62]To a mixture of (±)-cis-3-(tert-butyl-dimethyl-silanyloxy)-cyclopentanol (1.5 g, 6.93 mmol) (from Example 9a supra) and triphenylphosphine (1.99 g, 7.63 mmol) (Aldrich) in anhydrous tetrahydrofuran (60 mL) was added dropwise diethyl azodicarboxylate (1.2 mL, 1.32 g, 7.63 mmol) (Aldrich) at 0° C. Then after 2 minutes this was followed by the addition of diphenylphosphoryl azide (1.6 mL, 2.09 g, 7.63 mmol) (Aldrich) and the resulting solution was allowed to slowly warm up to room temperature. After stirring overnight the reaction mixture was partitioned between diethyl ether and water. The organic layer was collected, dried over sodium sulfate, filtered, and concentrated and the residue was purified by chromatography on a silica gel column using a 0–20% diethyl ether in hexanes gradient to give (±)-trans-(3-azido-cyclopentyloxy)-tert-butyl-dimethyl-silane as a colorless liquid. (Yield 1.2 g, 72%).
Wird geladen…